| Altenberger Dom | |
| Pushpin Map: | North Rhine-Westphalia#Germany |
| Coordinates: | 51.055°N 7.1334°W |
| Location: | Altenberg |
| Country: | Germany |
| Denomination: | Catholic |
| Dedication: | Assumption of Mary |
| Events: | restoration 19th century |
| Status: | church |
| Style: | Gothic |
| Parish: | Katholische Pfarrgemeinde St. Mariä Himmelfahrt am Dom Unserer Lieben Frau zu Altenberg |
| Diocese: | Diocese of Cologne |
| Altenberger Dom | |
| Denomination: | Evangelical Church in Germany |
| Parish: | Evangelische Kirchengemeinde |
The Altenberger Dom (or Bergischer Dom) is the former abbey church of Altenberg Abbey which was built from 1259 in Gothic style by Cistercians. Listed as a cultural heritage, it is located in Altenberg, now part of Odenthal in the Rheinisch-Bergischer Kreis, North Rhine-Westphalia, Germany. Until 1511, the church was the burial site of counts and dukes of Berg and the dukes of Jülich-Berg.
Badly damaged after the monastery was dissolved in 1803 due to the secularisation of Germany, the church was rebuilt with support from Friedrich Wilhelm IV of Prussia, who decreed in 1857 that it was to serve as a parish church simultaneously for a Catholic and a Protestant parish.
The German name has sometimes been translated to English as Altenberg Cathedral, but it was never a cathedral, a bishop's seat.
The Counts of Berg settled in the area east of Cologne, along the Dhünn river. Cistercians arrived from Morimond in their land, now Bergisches Land, in 1133. They founded Altenberg Abbey on the river, with a first church consecrated in 1160. The archbishop of Cologne, Konrad von Hochstaden, laid in 1259 the foundation of a larger church "St. Mariä Himmelfahrt" (Assumption of Mary). The choir of the new church, in Gothic style, was consecrated in 1276. The choir's floor plan is similar to that of the Cologne Cathedral, and the choir is similar to the destroyed choir of Royaumont, probably because the builders of Altenburg were familiar with that site. The church was built over 140 years and served as the abbey church for centuries.
During the secularisation of Germany, the monastery was dissolved in 1803. The buildings were used for a chemical plant. In 1815, a fire destroyed much of the buildings. Count Fürstenberg von Stammheim bought the ruins in 1833 and turned them over to the Prussian king, Friedrich Wilhelm IV, who was fond of medieval history.
The king supported the rebuilding of the Altenberger Dom, and also the completion of the Cologne Cathedral. He suggested already in the 1830s that the Altenberger Dom should be used by both Catholics and Protestants as a simultaneum, and finalized the idea in a royal decree of 1856.
The windows are predominantly in shades of grey (Grisaille), with some coloured windows, especially the large window in the west facade.
The church serves also as a concert venue. From May to October, sacred music and vespers take place regularly at 11:45 a.m.
The organ was built in 1980 by Klais Orgelbau, Bonn, an instrument of 6300 pipes, 88 stops, four manuals and pedal, with the last pedal stops added from 2007. The organ has been used for concerts and recordings.
According to a Benedictine tradition, members of the noble family owning the abbey were buried in the church.